Extraction devices, systems, and methods

ABSTRACT

Extraction devices, methods, and systems are disclosed. Example devices have a solvent chamber, a plant material chamber, a collection chamber, and a solvent return that create a sealed, closed-cycle extraction and/or solvent purification process. Any extractable plant material can be used in the disclosed devices, methods, and systems although in some examples some form of the cannabis plant is used.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending of U.S. patentapplication Ser. No. 15/090,426, filed Apr. 4, 2016, which is set toissue as U.S. Pat. No. 9,655,937 on May 23, 2017, which is a divisionalof U.S. patent application Ser. No. 14/794,665, filed Jul. 8, 2015, nowissued U.S. Pat. No. 9,327,210, which claims the benefit of ProvisionalPatent Application 62/080,889, filed Nov. 17, 2014, the contents ofwhich are all incorporated herein in their entirety.

BACKGROUND

Man has been extracting valuable compounds from plants throughout humantime. These extracts range from medicine to poisons, perfumes toflavorings and many others. In today's modern economy, plant extractsare still highly sought and valuable commodities.

One of the main extraction methods existing today is solvent-basedextraction in which the plant material containing the extractablecompounds is bathed or washed in a solvent. The solvent uptakes theextractable compounds from the plant material and combines the plantmaterial in a solution with the solvent. The compound solution is thenpurified to remove the solvent and recover the desired extractedcompound(s). Often, the purification process involves heating thesolution to “boil off” or volatilize the solvent from the solution,leaving the extracted compound(s) behind. Such extraction methodsusually use a solvent having a lower boiling point than that of theproducts so that the solvent can be boiled off without removing ordamaging the extracted compound(s).

Typically, the solvents used in such extraction processes arehydrocarbon-based or an alcohol, both of which have low boiling points,but can be explosive or flammable when volatilized. The explosive andflammable nature of the hydrocarbon-based extract processes has led tomany injuries and significant property damage as users try to performthese extraction processes.

Additionally, because the hydrocarbon solvents are easy to boil away,the solvents are oftentimes lost as a vapor to the atmosphere during theextraction and purification processes. The loss of the solvent makes theprocesses expensive to perform because additional solvent must be addedfor each new extraction process, which requires a large butane supply.

Some of the main solvent-based plant extract processes include thoseused to extract essential oils, Napetalactone (the main component ofcatnip) and various pharmaceutical compounds. Also, the rise of medicalmarijuana and the legalization of cannabis and cannabis-based productshas made cannabis plant extracts a legal and marketable pharmaceuticaland recreational commodity. One of the major extracts desired fromcannabis plants is hash oil. Hash oil is concentrated cannabinoids thatare extracted from the cannabis plant. The main psychoactive componentof marijuana is a cannabinoid called tetrahydrocannabinol, better knownas THC. Cannabinoids are a class of compounds that act on thecannabinoid receptors of the brain. The interaction of the cannabinoidswith the receptors is what causes a user to experience mood-enhancingeffects. Marijuana contains a variety of cannabinoids, THC andcannabidiol (CBD) being the major constituents, among many others.

The process of extracting hash oil from cannabis plant material ofteninvolves running butane, a hydrocarbon-based solvent, through the plantmaterial or soaking the plant material in butane to wash out thecannabinoids. The cannabinoid-rich solvent solution is then purified,often by heating it, which volatilizes the butane and leaves behind thecannabinoid extract. During the volatilization process, the butanesolvent is converted into a gaseous form that is then highly flammableand potentially explosive, which presents a significant danger topersonal safety and to any surrounding property.

Currently, to assist with recovery of the solvent from thesolvent-extract solution, many cannabinoid extract producers use a pump,often a refrigerant recovery pump, to move the vapors from the extractcontainer to a solvent storage container. The pump compresses thegaseous solvent vapors back into a liquid phase. Often these pumps havea mechanical pumping means, are electrically powered and are generallynot food safe. Further, the use of such pumps can be dangerous as thepumps are not designed to handle a flammable hydrocarbon. Solvent vaporscan leak from the pump and mix with the surrounding environment wherethey risk being sparked from either the operation of the pump itself orfrom other external sources. Additionally, any extract process using therecovered solvent risk being contaminated by pump lubricants or adversechemical reactions with the pump construction.

Therefore, there exists a need for solvent-based extraction processesthat can be performed safely without endangering operators and property.Additionally, there exists a need for a clean solvent conservationprocess to reduce the cost and increase the efficiency of the extractionprocess.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an example extraction device in accordance with aspects ofthe disclosure.

FIG. 1B is a variation of the example extraction device shown in FIG.1A.

FIG. 1C is another example extraction device in accordance with thisdisclosure.

FIG. 1D is yet another example extraction device according to aspects ofthe disclosure.

FIG. 1E is still another example extraction device according to thedisclosure.

FIG. 1F is another example extraction device in accordance with aspectsof the disclosure.

FIG. 1G is yet another example extraction device according to aspects ofthe disclosure.

FIG. 1H is still another example extraction device according to thedisclosure.

FIG. 2A is another example extraction device according to aspects of thedisclosure.

FIG. 2B is a variation of the example extraction device shown in FIG.2A.

FIG. 3 is still another example extraction device according to aspectsof the disclosure.

FIG. 4 is yet another example extraction device according to aspects ofthe disclosure.

SUMMARY

The disclosed extraction device has three chambers, the first is asolvent reservoir; the second is an extraction chamber, which holds thematerial containing the desired extractable material; and the third is acollection reservoir. Solvent flows from the solvent reservoir into theextraction chamber where the solvent is exposed to and washes throughthe material, dissolving and carrying away the extractables from theplant material. The solvent-extractables mixture is then collected inthe collection reservoir.

The extraction process conducted in the extraction device can be poweredby a thermal gradient/heat engine using the phase changing properties ofthe solvent. In the device disclosed herein, the solvent is maintainedin a low-energy, liquid state in the solvent-reservoir. The solventflows from the solvent reservoir through the extraction chamber thathouses the plant material. The contact of the solvent with the plantmaterial extracts compounds/products from the plant material. Thesolvent-extract solution flows into the collection reservoir which isthen warmed to a temperature at which the solvent enters a gaseous phasewhich causes the gaseous solvent to be released from the extractedcompounds.

By heating the collection reservoir to a temperature that volatilizesthe solvent, the solvent transforms to a gaseous phase and separatesfrom the solvent-extract solution leaving the extract behind. Theremaining extract solution may then be further refined if desired. Asthe collection reservoir is heated, the gaseous solvent is drawn througha solvent return channel into the solvent reservoir, which can bechilled either continuously or at specific times during the extractionprocess, such as when the gaseous solvent is released into the return.The gaseous solvent is pulled up the return channel due to the thermalgradient that is created between the chilled solvent reservoir and theheated collection tank.

In the gaseous state, the solvent expands, which creates a pressure inthe collection tank that forces the gaseous solvent through the solventreturn channel. The solvent return channel terminates in the chilledsolvent reservoir where the gaseous solvent condenses into a liquid atthe chilled temperature. The condensation of the gaseous solvent reducesthe volume of the solvent and thus generates a partial negative pressurewhich further draws gaseous solvent from the collection reservoir. Thecondensed solvent may then be recirculated through the device, orcollected and stored for use in later extraction processes.

To extract oils, plant material is placed in the extraction chamber.Solvent is then allowed to flow from the solvent storage chamber througha valve and into the extraction chamber where the solvent washes overthe plant material, extracting oils from the material as it percolatesthrough. The oil-solvent solution flows from the extraction chamber intothe collection chamber through a separate valve. In the collectionchamber, the solvent is separated from the extracted oils and is thenreturned to the storage chamber through the solvent return chamber. Theprocess is entirely sealed within the extraction device and is driven bygravity and the thermal gradient created by heating and/or chilling thevarious chambers.

DETAILED DESCRIPTION Extraction Devices

The disclosed extraction devices allow users to extract compounds fromplant material using a solvent. The process occurs in a sealed,closed-cycle environment, which allows the user to recover the solventand limits the likelihood of contamination of the final product. Plantmaterial is placed within an extraction chamber, which is then sealedwithin the device. The solvent is released from the solvent chamber intothe extraction chamber where it is left to extract compounds from theplant material. After the extraction process is completed, the solvent,which now carries the extracted compounds in solution, is drained into acollection reservoir. The collection reservoir is heated to volatilizethe solvent, which separates the solvent from the extracted compounds.

As the collection reservoir is heated, the solvent reservoir of thesolvent chamber can also be chilled, which creates a temperaturegradient between the solvent reservoir and the collection reservoir. Dueto the temperature gradient between the collection reservoir and thesolvent reservoir, solvent vapors are drawn through a solvent returnthat connects the collection reservoir and the solvent reservoir. Thesolvent vapors re-condense in the chilled solvent reservoir due to thelow temperature. The recovered liquid solvent may then be stored forlater extractions or may be reused in a continuous extraction or solventpurification process. The closed nature of this process helps tomaintain the purity of the solvent and the extracted compounds.

If a user desires, the solvent may be allowed to run through the plantmaterial continuously. By chilling solvent reservoir and heating thecollection reservoir, the solvent may be recirculated through the devicein a continuous manner while running through the material and extractingcompounds. The compounds concentrate in the collection reservoir sincethe solvent is constantly volatilized within the heated collectionreservoir. Once the user determines the extraction process is completed,the solvent can be collected in the solvent reservoir and stored forlater uses, if desired.

FIG. 1A is a side profile view of an example extraction device 100. Thedevice 100 is composed of three vertically stacked chambers: a solventchamber 110, an extraction chamber 130 and a collection chamber 150. Thechambers are linked by connectors 120 and 140, with a solvent return 180linking the solvent chamber 110 with the collection chamber 150.

The solvent chamber 110 features an enclosed solvent reservoir 112 thatis surrounded by an outer wall 114 separated from the solvent reservoir112 by a gap 113. The outer wall 114 wraps around the shared base 115,upon which the solvent reservoir 112 is also centered and disposed. Theshared base 115 may feature a drain 117 through which the user may drainor dispense contents from the gap, as desired.

The gap 113 allows the solvent reservoir 112 to be surrounded by a fluidbath (not shown) contained between the outer wall 114 and the exteriorsurface of the solvent reservoir 112. The fluid bath allows a user toadjust and/or regulate the temperature of the solvent reservoir 112 andthus the contents stored within. In the embodiment shown in FIG. 1A, asolvent is stored within the solvent reservoir 112 and is maintained oris cooled to a cool, low energy state by a surrounding cooling bath.Although not shown in FIG. 1A, the solvent reservoir 112 can be raisedby spacers to allow the cooling bath to contact its bottom surface andexpose greater surface area of the solvent reservoir 112 to the coolingbath.

The cooling bath can be contained in the gap 113 of the extractiondevice 100 shown in FIG. 1A. The cooling bath can be composed of amixture of dry ice (solid state CO₂) pellets and ethyl-alcohol(ethanol). This combination maintains the solvent reservoir at atemperature ranging from approximately −17° C. to −78° C., which issufficient to maintain the solvent in a liquid phase. In an example, thesolvent is butane, which has a boiling point ranging from −1° C. to 1°C. Additionally, maintaining the solvent reservoir at such a lowtemperature creates a large temperature differential between the solventreservoir and the collection reservoir that drives the heat enginepowering the device by re-condensing the returning gaseous solvent backinto a liquid. Other suitable cooling bath mixtures may be used, as longas the bath maintains the solvent reservoir below the solvent boilingpoint. It is also desirable to maintain the solvent reservoir at as lowa temperature as possible as the efficiency of the system is driven, inpart, by the magnitude of the temperature gradient that exists betweenthe chilled solvent reservoir, and the heated collection reservoir.

The side walls of the solvent reservoir 112, the outer wall 114 and thebase 115 are constructed of food grade stainless steel, but also may beconstructed of other suitable medical and/or food grade materials inother examples. Other such suitable materials include those that arenon-reactive with the chosen solvent and those having thermalconductivity. The thermal conductivity allows the solvent reservoir 112,and the contents held within, to be thermally adjusted by thesurrounding bath, a high thermal conductivity hastening the transfer ofthermal energy from the surrounding fluid bath to the solvent reservoir112 and contents within. Further, each part, the solvent reservoir 112,outer wall 114 and the base 115, may be constructed of the same ordifferent materials.

Any impurities in the solvent affect the properties of the solvent andmay reduce its capacity to extract compounds and/or reduce the thermalcapacity, thereby decreasing device and process efficiency.Additionally, any impurities in the solvent may be transferred into theextracted compounds where they may reduce the efficacy, change thequality or cause harm to users of the final product and/or requireadditional or costly post-extraction processes to remove the entrappedimpurities. To further aid in the avoidance of potential impurities,medical and/or food grade materials and design techniques are usedthroughout the device.

A safety vent, not shown in the figures, may be disposed atop thesolvent reservoir 112. The safety vent allows built-up, gaseous solventto be safely removed from the solvent reservoir 112 to reduce the riskof system over-pressure incidents. The vent extends from the uppersurface of the solvent reservoir 112 to at least the upper plane of theouter tank 114 to ensure that if the solvent reservoir 112 is submergedin a cooling bath, the outlet of the vent remains open and unblocked.The safety vent is a pipe attached to the solvent reservoir 112 and influid communication with the tank interior. Positioned within the safetyvent is a diaphragm calibrated to a pre-set pressure. If the interiorpressure of the solvent reservoir 112 exceeds the pre-set pressure, thediaphragm opens, venting stored solvent vapors and decreasing theinternal pressure of the solvent reservoir 112. Once the internalpressure has fallen to a safe level, below the diaphragm pre-set triggerpressure, the diaphragm closes and reseals the solvent reservoir 112.The one-way nature of the safety vent prevents any outside gas fromentering the device. Such contamination could decrease the efficiency ofthe device and/or contaminate the product.

A view port 118 is disposed on the upper surface of the solventreservoir 112, as shown in FIG. 1A. The view port 118 is constructed ofa transparent material set into a metal housing. The view port 118 isreleasably mounted to a protrusion from the solvent reservoir 112 by athreaded connection, but may be permanently affixed in other examples. Aseal may be disposed between the view port 118 and the solvent reservoir112 to prevent solvent vapors from leaking out of the solvent reservoir112 and to prevent contamination of the solvent by the outsideenvironment. The view port 118, if releasably connected, may be removedwhen access to the interior of the solvent reservoir 112 interior isnecessary, such as for cleaning and maintenance purposes. Alternatively,the view port 118 may extend through a side wall of the solventreservoir 112 and the outer wall 114. Further, the view port 118 mayfeature a light to illuminate the interior of the solvent reservoir 112,which could include LED lighting, for example. The lighting source maybe located on an interior side of view port 118 where it is exposed tothe interior of the solvent reservoir 112. Alternatively, the lightingsource may be located in a manner that isolates the source from theinterior of the device 100 and/or the exterior environment surroundingthe device 100.

The interior of the solvent reservoir 112 can feature markings to assista user in measuring the quantity and/or quality of the interiorcontents. The markings can be viewable to a user through the view port118. In other embodiments of the device 100, the interior markings maybe absent as desired or required by the user, use and/or design of thedevice 100. Also, a temperature gauge, like a thermometer, and/or apressure gauge can also be included to measure the respectivetemperature and/or pressure in the solvent reservoir or any otherchamber or reservoir described herein.

A solvent inlet 116 extends from the surface of the solvent reservoir112 and is the entry point for contents, such as a solvent, to beintroduced into the solvent reservoir 112. In the embodiment of FIG. 1A,the solvent inlet 116 is a valve to which an external solvent source canbe connected. Opening the solvent inlet 116 allows the solvent to flowfrom the external source into the solvent reservoir 112. The user canassess and observe the fill progress through the view port 118. Once thedesired fill level is achieved, the solvent inlet 116 is closed and theexternal solvent source disconnected.

Alternatively, the solvent inlet 116 can be a spring-loaded inlet valve,similar to those found in butane lighters and refillable air cylinders.An external solvent source (not shown) containing the solvent or othersubstance to be introduced into the solvent reservoir 112 is connectedto the solvent inlet using an appropriate connector. The solvent thenflows through the solvent inlet 116 and collects within the solventreservoir 112. Once the solvent reservoir is filled to a level desiredby a user, the external solvent source is disconnected, at which timethe solvent inlet 116 is sealed by the internal spring. Using such avalve minimizes or prevents contaminants from the external environmentfrom entering the device 100 through the solvent inlet 116.Contamination of the device 100 by the external environment canadversely affect the solvent and/or the product.

The solvent return 180 connects to the solvent reservoir 112 via aninlet 186. The connection between the solvent return 180 and the solventreservoir 112 can be releasable or permanent. In the embodiment shown inFIG. 1A, the connection is a permanent weld affixing the solvent return180 to the solvent chamber 110.

The other end of the solvent return 180 is welded to the top of asanitary cap 146. In the example shown in FIG. 1A, the solvent return180 is a rigid structure running between the solvent chamber 110 and thetop of fitting 146, allowing fluid communication between the solventreservoir 112 and the collection reservoir 152. A rigid solvent return180 can provide structural support and elevate the solvent chamber 110when the device 100 is assembled.

The solvent chamber 110 is connected to the extraction chamber 130 via aconnector 120. The connector 120 features a valve 122 to regulate theflow of the solvent as it exits the solvent chamber 110. The valve 122is affixed to a threaded extension extending from the shared base 115.Alternatively, the valve 122 can be connected using a compressionfitting or directly welded to the shared base 115. The extension is influid communication with the solvent reservoir 112. The valve 122 can becontrolled manually by a user or electronically controlled by a user orcontroller. The valve 122 may be variably controlled so that the rate ofsolvent flowing through it may be varied by a user or other controlmeans. Additionally, there may be a view port disposed about theconnector 120 or valve 122 that allows a user to observe the flow ofsolvent from the solvent chamber 110.

The connector 120 is further affixed to a sanitary cap 124. The sanitarycap 124 is a flat disk, having a chamfered circumference and has athreaded extension to which the valve 122 of the connector 120 issecured. Alternatively, the valve 122 can be connected using acompression fitting or directly welded to the sanitary cap 124. A sealcan be disposed on the side opposite the threaded extension andinterfaces with a mating surface of a top sanitary ferrule 134 of theextraction chamber 130. The top sanitary ferrule 134 of the extractionchamber 130 and the sanitary cap 124 of the connector 120 are joined bya sanitary connection such as a single pin-hinged clamp. The sanitaryconnector affixes and compresses the chamfered perimeters of thesanitary cap 124 and the top sanitary ferrule 134 of the extractionchamber 130 to form a seal. Other suitable releasable connections may beused to join the chambers 110 and 130, such as threaded connections.

The extraction chamber 130 of the device 100 as shown in FIG. 1 includesthe top sanitary ferrule 134 discussed above, a plant material chamber132, a bottom sanitary ferrule 136, an outer wall 138 spaced a distance139 about the plant material chamber 132, a circular base 137 and adrain 158. The plant material chamber 132 is disposed between the topsanitary ferrule 134 and the bottom sanitary ferrule 136. In theembodiment shown in FIG. 1A, the plant material chamber 132 isconstructed of food-grade stainless steel, as are the other componentsof the extraction chamber 130. The plant material chamber 132 canfeature view ports to allow a user to observe the extraction process. Aswith the solvent chamber, the plant material chamber can also include athermometer or other temperature gauge and a pressure gauge to measurethe temperature and the pressure of the plant material chamber.

Alternatively, the plant material chamber 132 can be constructed ofglass. The transparent nature of a glass plant material chamber 132allows a user to observe the extraction process. The chamber 132 mayalso be constructed of other suitable transparent material. Suchsuitable materials include those that do not adversely react with thesolvent, extract and/or plant materials.

The top sanitary ferrule 134 and bottom sanitary ferrule 136 of theextraction chamber 130 are constructed of food-grade stainless steel andare disposed atop and below the plant material chamber 132. The topsanitary ferrule 134 is affixed to or can be an integrated part of theplant material chamber 132. The bottom sanitary ferrule 136 is affixedto the base of and is in fluid communication with the plant materialchamber 132. Both the top sanitary ferrule 134 and bottom sanitaryferrule 136 can have an open geometry. That is, the inner diameters ofthe top and bottom sanitary ferrule 134, 136 are substantially the samedimensions as the inner diameter of the plant material chamber 132. Thisallows the user easier access to the interior of the plant materialchamber 132.

In the example embodiment in which the plant material chamber 132 isconstructed of glass, the plant material chamber 132 is a glass tube,the top and bottom sanitary ferrules 134, 136 providing the top and basefor the chamber 132. The top sanitary ferrule 134 and bottom sanitaryferrule 136 can have an interior lip on which seals can be disposed. Theupper and lower circumference of the glass plant material chamber 132rests on the seals respectively. Alternatively, the top 134 and bottom136 may feature seals about their interior surface, the seals contactingthe outer periphery of the glass plant material chamber 132, preventingthe interior of the chamber from external environmental intrusion.

In the glass plant material chamber embodiment, a support structure canextend between the top sanitary ferrule 134 and the bottom sanitaryferrule 136, locking the two pieces together with the glass plantmaterial chamber in between. The support structure can be composed ofthreaded rods with nuts disposed on either side of the top sanitaryferrule 134 and the bottom sanitary ferrule 136. The user tightens thenuts about the top sanitary ferrule 134 and bottom sanitary ferrule 136to constrain the glass plant material chamber between them.

The outer wall 138 is separated from the plant material chamber 132 by agap distance 139 about the periphery of the plant material chamber 132.The circular base 137 is connected to the outer wall 138 and disposedabout the perimeter of the plant material chamber 132 to form a tank asdefined by the gap 139. The gap 139 can be filled with a temperatureregulating bath, such as a cooling bath as described above in regards tothe solvent chamber, or by a heating/warming bath and can be selectivelyheated/cooled to help control the temperature gradient between thesolvent chamber and the collection chamber. For example, a user can fillthe gap 139 surrounding the plant material with a warming bath after theextraction process within the plant material chamber 132 is complete. Bywarming the chamber 132, any remaining solvent within the chamber 132can be volatilized and then recovered and used for future extractionprocesses.

In the embodiment shown in FIG. 1A, the gap 139 is filled with apre-warmed fluid or mixture after the extraction process is completed.The temperature of the fluid or mixture can be pre-selected by the userto optimize solvent recovery. Once the solvent has been sufficientlyrecovered, the surrounding bath can be drained through a drain 135. If asteady high temperature bath is required, the drain 135 can be partiallyopen to drain away cooler fluid as the gap 139 is replenished with hotfluid.

Alternative methods of heating the plant material chamber 132 can beused, such as resistive heating elements, thermoelectric heaters andother heating sources. As with the temperature bath discussed above, theheating sources can be temperature controlled to achieve a desiredtemperature within the plant material chamber 132, if necessary ordesired.

The bottom sanitary ferrule 136 is attached to the connector 140 in amanner similar to the top sanitary ferrule 134 connection to theconnector 120. The connector 140 is affixed to a top sanitary cap 144 towhich the bottom sanitary ferrule 136 of the extraction chamber 130 isconnected by a sanitary connection. The top sanitary cap 144 features aseal disposed about the inner perimeter of the cap 144 and contacts asurface of the bottom sanitary ferrule 136, such that when the sanitaryconnection, such as a single pin-hinged clamp, is engaged, the chamferedbottom sanitary ferrule 136 and chamfered top sanitary cap 144 compressthe seal. In the embodiment shown in FIG. 1A, the seal on the topsanitary cap 144 features a mesh filter disposed across the innerdiameter of the top sanitary cap 144. The filter prevents plant materialfrom the plant material chamber 132 from traveling through the connector140.

The connector 140 has a top sanitary cap 144, discussed previously, abottom sanitary cap 146 and a valve 142. The valve 142 is attached to athreaded extension of the top sanitary cap 144. Alternatively, the valve142 can be connected using a compression fitting or directly welded tothe top sanitary cap 144. The threaded extension of the top sanitary cap144 is in fluid communication with the interior of the plant materialchamber 132. The valve 142 can be manually controlled by a user or canbe electronically controlled by a user or controller. Additionally,there may be a view port disposed about the connector 140 or valve 142that allows a user to observe the flow of solvent-extract solution fromthe extraction chamber 130. The bottom sanitary cap 146 is connected tothe valve 142 in a similar manner as the top sanitary cap 144. Thebottom sanitary cap 146 includes a threaded extension to which the valve142 is affixed and the threaded extension is in fluid communication withthe collection chamber 150. Alternatively, the valve 142 can beconnected using a compression fitting or directly welded to the bottomsanitary cap 146.

The collection chamber 150 shown in FIG. 1A features a collectionreservoir 152, an outer wall 154, a sanitary ferrule 156, a base 160,spacers 162, a pressure indicator 170 and a solvent return outlet 184.The collection reservoir 152 is a tank of a similar construction as thesolvent reservoir 112. The collection reservoir 152 collects thesolvent-extract solution from the extraction chamber 130. The collectionreservoir 152 is elevated from the base 160 by spacers 162 although inalternative examples the collection reservoir 152 sits directly on thebase 160. In the example shown in FIG. 1A, a fluid bath is disposedabout the reservoir 152 and is contained by the outer wall 154. Thespacers 162 allow the bath to contact more surface area of thecollection reservoir 152.

The sanitary ferrule 156 is connected to a top plate 157 of thecollection reservoir 152, as shown in the embodiment of FIG. 1A. Thesanitary ferrule 156 can be removably connected, such as by a threadedconnection or other removable attachment options, to the top plate 157.The top plate 157 can also be removably connected to the collectionreservoir 152 or permanently attached by welding or other permanentattachment options. Alternatively, the sanitary ferrule 156 can beintegrated with the top plate 157 to form a single piece that isremovably attached to the collection reservoir 152. The sanitary ferrule156 is in fluid communication with the collection reservoir 152 of thecollection chamber 150. Further, a view port can be disposed on thesanitary ferrule 156, top plate 157 or in any other location such that auser may observe the contents of the reservoir 152.

A drain outlet 158 is disposed on the outer wall 154 and is in fluidcommunication with the gap surrounding the collection reservoir 152. Thefluid bath surrounding the collection reservoir 152 can be drainedthrough the drain outlet 158 after the extraction process is completed.

A pressure indicator 170 is in fluid communication with the interior ofthe collection reservoir 152 and allows a user to observe and monitorthe interior pressure. The pressure indicator can indicate a positivepressure, a negative pressure or combination thereof. The pressureindicator 170 is disposed on a sidewall of the reservoir 152 but may bedisposed elsewhere as required or desired.

The solvent return 180 is connected to the outlet 184 and is disposed onthe sanitary ferrule 156 of the collection reservoir 152. The solventreturn 180 is in fluid communication with the collection reservoir 152when the sanitary ferrule 156 is in place and allows gaseous solvent totravel from the collection reservoir 152 to the solvent reservoir 112.The solvent return 180 may be permanently or releasably connected to thesanitary ferrule 156. In the embodiment shown in FIG. 1A, the solventreturn 180 is welded to the sanitary ferrule 156.

The solvent return 180 is a food-grade stainless steel conduit thatfluidly links the collection chamber 150 with the solvent storagechamber 110. The solvent return 180 provides the path for the gaseoussolvent to return to the solvent chamber and re-condense to its liquidform, thus providing a fully-sealed extraction system. The solventreturn 180 has a valve 182 to regulate the flow of gaseous solvent fromthe collection reservoir 152 to the solvent reservoir 112. The valve 182is in-line with the solvent return 180 and is connected via releasablethreaded connections. In the embodiment of FIG. 1A, the solvent return180 is welded to the solvent storage chamber 110 and the sanitaryferrule 156 of the collection reservoir 152. While the valve is disposedin the solvent return 180, the solvent chamber 110 and the sanitaryferrule 156 of the collection reservoir 152 are effectively a singleunit linked by a rigid form of the solvent return 180. By separating thesolvent return 180 at the valve 182, the two sections, the solventchamber 110 and the sanitary ferrule 156 may be disjoined from oneanother. The rigid solvent return 180 provides structural support forthe vertically stacked chambers and a rigid, parallel return path tofully seal the extraction system.

Alternatively, in example devices that are self-supporting or aresupported externally, the solvent return 180 can be a flexible orsemi-rigid connection. Such connections can include a hose, flexiblepiping, high pressure flexible line or other suitable connection option.

A purge valve 188 is included on the solvent return 180. The purge valve188 is disposed on the solvent return 180 such that it is in fluidcommunication with the interior of the collection reservoir 152,regardless of the position of the valve 182 on the solvent return 180.The purge valve 188 allows the user to purge or decrease the amount ofoxygen within the device 100 before starting an extraction processand/or loading the solvent. When using a combustible or flammablesolvent, the purging of oxygen from the system assists in lowering therisk of solvent ignition. The valve 188 may be a one- or two-way valveor may be actuated by a user or other control means. The purge of oxygenor other atmosphere within the device may be accomplished by introducinga secondary, inert gas that displaces the existing gas within the device100 through the valve 188. Alternatively, a vacuum can be created withinthe device, the evacuated air being drawn through the valve 188 by amechanical means. By creating a vacuum or low pressure within thedevice, the amount of oxygen within the device is preferably below thelevel required for ignition and/or combustion of the solvent.

Additionally, the purge valve 188 can act as a pressure relief valve forthe collection reservoir 152. The purge valve 188 is in fluidcommunication with the interior of the collection reservoir 152, openingthe purge valve 188 can vent stored pressure from within the interior ofthe collection reservoir 152 as necessary.

FIG. 1B is an alternative embodiment of the device 100 of FIG. 1A. Thedevice 100, as shown in FIG. 1B, includes a view port 145 disposed onthe bottom sanitary cap 146 of the connector 140. The view port 145allows the user to view the interior of the collection reservoir 152. Alight source, such as LEDs, can be disposed about the interior, orexterior, of the view port 145 and light the interior of the collectionreservoir 152 for improved user viewing. The collection reservoir 152can feature internal markings similar to those of the solvent reservoir112, assisting the user in measuring the filled volume of the collectionreservoir 152 through the view port 145.

FIG. 1C shows another alternative embodiment of the disclosed extractiondevices. The extraction device 190 has a solvent chamber 192, eightplant material chambers 194, and a collection chamber 196. The solventchamber 192 is connected to the plant material chambers 194 by aflexible hose 198. The eight plant material chambers 194 are positionedin parallel with each other in the between the solvent chamber 192 andthe collection chamber 196. Any suitable number of plant materialchambers 194 could be substituted for the eight that are shown in FIG.1C. The plant material chambers 194 are shown mounted to a rack 200 witha pipe 202 that serves as a type of manifold to provide a pathway forthe flexible hose 198 that connects the solvent chamber 192 with theplant material chambers 194. The plant material chambers 194 areconnected by respective flexible hoses 204 to the collection chamber196. A pump 206 is shown in the extraction device 190 of FIG. 1C whichis connected to both the solvent chamber 192 and the collection chamber196 to aid in the extraction process although, as discussed above, apump is not necessary to execute a proper extraction process.

Additionally, a temperature control unit 208 is shown connected to thesolvent chamber 192 in FIG. 1C. The temperature control unit 208controls the temperature of the solvent chamber 192 throughout theextraction process. Optionally, the temperature control unit 208 couldbe connected to other components of the extraction device 190, as neededor desired. In the example shown in FIG. 1C, the temperature controlunit 208 could be a self-contained refrigeration unit although otherexample units that are capable of controlling the temperature of one ormore components of the device can be additionally or alternatively used.A solvent return 209, 211 connects the collection chamber 196 and thesolvent chamber 192 to recapture the gaseous solvent after theextraction process is complete and transport it back to the solventchamber 192 while it recondenses to its fluid form. In this example, thesolvent return 209, 211 is a two-part hose with an in-line pump 206 thataids in the recovery process.

FIG. 1D shows another example extraction device 210 that includes asolvent chamber 212, a pair of plant material chambers 214, and acollection chamber 216. The solvent chamber 212 and the plant materialchambers 214 are connected by a flexible hose 218 although the hosecould be a rigid pipe or some combination of a rigid component and aflexible hose in other examples. The collection chamber 216 is connectedto an expansion chamber 224 that helps prevent fluid extract or solventfrom being pulled into the pump 220. Instead, the excess fluid is pulledinto the expansion chamber 224 where it collides with the internal wallsof the expansion chamber 224 and transforms phases into a gas where itis then stored. Similar to the pump in FIG. 1C, the extraction device210 shown in FIG. 1D, has a pump 220 that is connected to both thesolvent chamber 212 and the expansion chamber 224 to aid in theextraction process.

FIG. 1E shows yet another example extraction device 226 with a solventchamber 228, three plant material chamber 230 positioned in parallel,and a collection chamber 232. As with the other example extractiondevices, the each of the chambers 226, 230, and 232 are connected viaeither a flexible hose, rigid pipe, or some other connector thatprovides fluid communication between the chambers. In the example shownin FIG. 1E, the three plant material chambers 230 are shown to beconnected in parallel between the solvent chamber 228 and the collectionchamber 232 in a similar fashion to the other examples discussed above.The extraction device 226 of FIG. 1E also has a secondary collectionchamber 234. In this example, some portion of the gaseous solvent isevaporated from or otherwise separated from the extract itself in thecollection chamber 232. Remaining fluid can be moved into the secondarycollection chamber 234 for further separation of the gaseous solventfrom the extract resulting in a purer extract remaining in thecollection chamber 232. The solvent return 236, 238 is a two componentflexible hose or tube in this example with an in-line pump 240 torecapture the gaseous solvent that evaporates or otherwise separatesfrom the extract collected in the collection chamber 240.

FIGS. 1F-1H show simplified example extraction devices 242, 262, and280. The extraction device 242 has a solvent chamber 244, a plantmaterial chamber 246, and a collection chamber 248. The solvent chamber244 and the plant material chamber 246 are connected by a flexible hose250 or could be connected by another connector like a rigid pipe, forexample. The plant material chamber 246 is connected to the collectionchamber 248 by a right connector 252 in this example. The collectionchamber 248 is connected to the solvent chamber 244 by the solventreturn 254, 256, 258, 260 that includes flexible hoses 254, 256 and anin-line pump 258 with an in-line filter 260 in this example. FIG. 1Gshows still another embodiment of a disclosed extraction device 262having a solvent chamber 264, a plant material chamber 266, and acollection chamber 268. The solvent chamber 264 is connected to theplant material chamber 266 by a flexible hose 270 and the plant materialchamber 266 is connected to the collection chamber 268 by a rigidconnector 272. The collection chamber 268 is connected back to thesolvent chamber 264 for recapturing gaseous solvent released from thesolvent-extract solution in the collection chamber 268 by a solventreturn 274, 276, 278, which includes a pair of flexible hoses 274, 276and a pump 278.

FIG. 1H shows still another embodiment of an example extraction device280 that is a simpler version of the extraction device shown in FIG. 1G.The extraction device 280 of FIG. 1H is a solvent chamber 282, a singleplant material chamber 284, and a collection chamber 286. As with theexample shown in FIG. 1G, the solvent chamber 282 is connected to theplant material chamber 284 by a flexible hose 288 and the plant materialchamber 284 is connected to the collection chamber 286 by a rigidconnector 290. The solvent return 292, 294, 296 connects the collectionchamber 286 and the solvent chamber 282 to provide the fluid pathway torecover the gaseous solvent released from the solvent-extract solutionproduced in the collection chamber 286 during the extraction process.

FIG. 2A is another embodiment of the extraction device 200 that iscomposed of three different sections, a solvent chamber 210, anextraction chamber 230 and a collection chamber 250, which are connectedby connectors, 220 and 240, and a return 280. The solvent chamber 210includes a solvent reservoir 212 surrounded by an outer wall 214 andseparated by a gap 213. The outer wall 214 and solvent reservoir 212 areattached to a shared base 215. The shared base 215 includes a drain 217through which the contents of the gap 213 can be drained.

The solvent reservoir 212 has a removable cap, 218 a or 218 b that auser can remove for improved access to the interior of the reservoir212. Alternatively, the solvent reservoir 212 is not required to have acap and can be completely enclosed, which may be desirable to preventcontamination of the solvent by an external environment.

The gap 213 allows the solvent reservoir 212 to be surrounded by a fluidbath. As discussed with the previous embodiments, the fluid bath is acold bath that can be composed of many different materials and mixtures.The low temperature of the solvent chamber 210 and the heated collectionchamber 230 create a temperature gradient that drives the solventrecovery process.

Additionally, a splashguard 219 is included about the inner periphery ofthe outer wall 214. The splashguard 219 is affixed to the outer wall 214and extends over the gap and partially covers the periphery of thesolvent reservoir 212. Alternatively, the splashguard 219 can be aremovable element that interfaces with the outer wall 214 for support.

The solvent reservoir 212, the outer wall 214 and the base 215 are madeof food-grade stainless steel, a non-reactive material that will notcontaminate the solvent or finished product. Alternative materials canbe used for the construction of the various components to preserve thequality of the extract and solvent.

The solvent reservoir 212 includes a view port, 218 a or 218 b, throughwhich the user can observe the interior of the reservoir 212. Aspreviously discussed, the view port, 218 a or 218 b, include atransparent top portion through which the user can observe the interiorof the solvent reservoir 212. Additionally, lights, such as LEDs, can bedisposed about the interior periphery, or exterior, of the view port 218a or 218 b to assist the user with observations.

In the example device 200 shown in FIG. 2A, either of the elements 218 aand 218 b can be a cap and/or a view port. That is, 218 a can be a viewport and 218 b can be a solid cap, or vice versa. Alternatively, both218 a and 218 b can be view ports, with one or both removably connectedto the solvent reservoir 212.

A pressure gauge 211 and a solvent inlet 216 are in fluid communicationwith the interior of the solvent reservoir 212. The pressure gauge 211allows the user to determine an interior pressure of the reservoir 212.The user can respond to pressure indications as necessary, such as byventing stored pressure within the solvent reservoir 212 to prevent anover-pressurization event which could lead to catastrophic failure ofthe device. The interior pressure of the solvent reservoir 212 can bevented through the solvent inlet 216 by actuation of the valve. Theactuation of the valve can be done by a user or remotely by a manual orautomatic actuator. Additionally, the pressure gauge can be configuredto automatically actuate the valve at a given pressure to prevent anundue accumulation of pressure or volatilized solvent.

Solvent from the solvent reservoir 212 flows into the extraction chamber230 through the connector 220. The connector 220 includes a sanitaryvalve 222 that is disposed between and in fluid communication with thesolvent chamber 210 and the extraction chamber 230. The sanitary valveis held between the two chambers using a compression fitting.Alternatively, the sanitary valve 222 can be directly welded to one orboth of the solvent chamber 210 and the extraction chamber 230.

The connector 220 further includes a sanitary cap 224 to which the valve222 is also connected. The sanitary cap 224 and the sanitary ferrule 234form a sanitary connection between the connector 220 and the extractionchamber 230 when a compression clamp, such as a single pin-hinged clampis locked about the chamfered circumference of the two pieces 224 and234.

A solvent return 228 is also included on the sanitary cap 224. Thesolvent return is in fluid communication with the plant material chamber232 of the extraction chamber 230 and the solvent reservoir 212. As theremaining solvent within the plant material chamber 232 is volatilizedafter the extraction process, the solvent vapors travel through thesolvent return 228 and recondenses in the chilled solvent reservoir 212.The solvent return 228 enters the solvent reservoir 212 and extends pastthe level of the solvent within. In doing so, the solvent within thereservoir 212 cannot travel back down the return 228 and into theextraction chamber 230. A valve 226 is disposed on the solvent return228 to allow the user to regulate the flow of the volatilized solventfrom the extraction chamber 230.

The extraction chamber 230 includes a plant material chamber 232, anouter wall 238, a circular base 237, a top sanitary ferrule 234 and abottom sanitary ferrule 236. As discussed previously, the components ofthe extraction chamber 230 are constructed from food-grade stainlesssteel using food-grade manufacturing techniques and processes.

The plant material chamber 232 is topped with a removable or integratedtop sanitary ferrule 234 that is a portion of the sanitary connectionbetween the extraction chamber 230 and connector 220. The top sanitaryferrule 234 has an open diameter approximately equal to that of theinner diameter of the plant material chamber 232 to allow the usereasier access to the interior of the plant material chamber 232. Theextract containing plant material is placed in the plant materialchamber 232.

A circular base 237 is disposed about the periphery of the plantmaterial chamber 232 and spaces the outer wall 238 a distance 239 fromthe said periphery. The circular base 237 provides the base for the tankformed by the outer wall 238 and gap 239. The gap 239 can be filled witha temperature bath, preferably a warm or hot water bath, after theextraction process is completed. The temperature bath heats the plantmaterial chamber 232, which volatilizes the remaining solvent that thenflows through the solvent return 228 back into the solvent reservoir212.

The outer wall 238 includes openings 233 a and 233 b through which thetemperature bath can be added and circulated about the plant materialchamber 232. The temperature bath can flow in through the opening 233 a,filling the gap 239 from the bottom up. At the top, the temperature bathflows out through the opening 233 b, which allows for a steadyreplenishment of pre-heated temperature bath to be circulated about theplant material chamber 232. The temperature bath exiting the opening 233b is at a lower temperature, as it has transferred thermal energy to theplant material chamber 232, then the pre-heated temperature bathentering the gap 239 through the opening 233 a. The temperature bathcirculating within the gap 239 can have a pre-selected and/orcontrollable temperature, which can be controllable by a user orelectronic controller, in order to achieve maximal efficiency of solventrecovery.

The bottom sanitary ferrule 236 can be attached or integrated to thebase of the plant material chamber 232. The bottom sanitary ferrule 236interfaces with a sanitary cap 244 of the connector 240 to form asanitary connection between the extraction chamber 230 and the connector240.

The base of the plant material chamber 232 and/or the sanitary ferrule236 can include a filter that prevents plant material from entering theconnector 240 but allows the extract-rich solvent solution to passthrough. Additionally, the filter can be a filter that removes or limitsthe amount of undesirable compounds that pass from the extractionchamber 230 into the collection chamber 250.

The connector 240 includes a sanitary valve 242 disposed between asanitary cap 244 and a bottom sanitary cap 246. The connector 240facilitates and regulates fluid communication between the extractionchamber 230 and the collection chamber 250.

The collection chamber 250 includes a collection reservoir 252, an outertank 254 and a shared top 257. A sanitary ferrule 256 is affixed orintegrated with the shared top 257. The sanitary ferrule 256 interfaceswith the lower sanitary cap 246 of the connector 240 to form a sanitaryconnection between the extraction chamber and the connector 240.

The collection reservoir 252 is affixed or integrated with the sharedtop 257. This arrangement allows the suspension of the collectionreservoir 252 within the outer tank 254. The outer tank 254 is filledwith a temperature bath that surrounds the collection reservoir 252 andassists with the separation of the extract from the solvent and therecovery of the solvent. Preferably, the temperature bath is a warm orhot water bath that transfers sufficient thermal energy into thesolvent-extract solution within the collection reservoir 252 tovolatilize the solvent. Volatilizing the solvent separates the solventfrom the solvent-extract solution and the solvent vapors rise throughthe solvent return 280 to be recovered in the solvent reservoir 212.

The outer tank 254 includes an inlet 258 a through which the temperaturebath can be introduced into the outer tank 254. The inlet 258 a can alsofunction as a drain to drain the bath contained by the outer tank 254after a refinement or extraction process is completed.

The outer tank 254 includes an outlet 258 b, through which thetemperature bath exits the outer tank 254 as additional temperature bathis introduced though the inlet 258 a. As newly heated temperature bathis introduced through the inlet 258 a, temperature bath can be displacedthrough the outlet 258 b. The outlet 258 b can be connected to the inlet233 a of the outer wall 238 of the extraction chamber 230. In thisarrangement, the temperature bath is circulated about the collectionreservoir 252 before being displace to circulate about the plantmaterial chamber 232.

The collection reservoir 252 includes an inclined floor 253 that can beadded to or integrated with the reservoir 252. The inclined floor 253directs the extract solution to the outlet 255 through which the extractsolution can be removed from the collection reservoir 252.

Alternatively, the collection reservoir 252 can be constructed to have asloping floor itself. Such a design removes the need for an inclinedfloor 253 within the reservoir 252. The inclined floor 253 or thealternative embodiment of a collection chamber with an integratedslopped floor can have an adjustable incline in some examples that canbe adjusted manually or automatically.

A pressure gauge 270 is in fluid communication with the interior of thecollection reservoir 252 and indicates the stored pressure to a user.The pressure indicator 270 can indicate a positive pressure, a negativepressure or a combination thereof. As the solvent-extract solution isheated and the solvent is vaporized, the pressure within the solventreservoir 252 rises if the solvent vapors are constrained. The pressuregauge allows the user to measure the interior pressure of the reservoir252 so that the user can take appropriate safety action should theinternal pressure of the collection chamber approach a critical level.Venting the constrained pressure can prevent catastrophic failure of thedevice 200.

A solvent return 280 fluidly connects the collection reservoir 252 andthe solvent reservoir 212. The return 280 assists the recovery of thesolvent after the extraction process is completed. As the solvent withinthe collection reservoir 252 is heated and volatilized, the volatilizedsolvent flows up the return 280 and into the chilled solvent reservoir212 where it recondenses back into liquid solvent. The return 280includes a sanitary ferrule 284 extending from the collection reservoir252 a length of conduit 283 and a sanitary valve 282. The length ofconduit 283 is connected to the sanitary ferrule 284 by a sanitaryconnection and extends vertically to the valve 282, which is connectedby a sanitary connection 288.

The sanitary valve 282 regulates and controls the flow of volatilizedsolvent from the collection reservoir 252 to the solvent reservoir 212.The return 280 extends from the sanitary valve 282 and into the solventreservoir 212 with an outlet 286 located above the level of the solvent.As the vapors flow through the outlet 286 and recondense into liquidsolvent, the elevated position of the outlet 286 prevents liquid solventfrom flowing back down the return 280.

The vertical nature of the solvent return 280 shrinks the overallfootprint of the device 200.

FIG. 2B is an embodiment of an extraction device 200 similar to thedevice of FIG. 2A with some modifications and additions.

The solvent chamber 210 of the device 200 of FIG. 2B has a single viewport 218 through which the user can observe and monitor the interior ofthe solvent reservoir 212.

The return 280 of the device 200 of FIG. 2B is similar in nature to thesolvent return 180 of the device 100 of FIGS. 1A and 1B. The return 280is in fluid communication with the collection chamber 250 through thesanitary ferrule 284. The return 280 includes a sanitary valve 282disposed along its length. The sanitary valve 282 regulates and controlsthe flow of the volatilized solvent from the collection reservoir 252into the solvent reservoir 212. The return 280 terminates at the top ofthe solvent reservoir 212 at an outlet 286.

An oxygen purge element 285, like that of 188 of FIGS. 1A and 1B, isconnected to and in fluid communication with the collection reservoir252. The oxygen purge element 285 assists the user in purging the deviceof oxygen and other unwanted gases prior to an extraction processoccurring.

The return 280 also features an outlet and valve 287. The outlet andvalve 287 allows access to the device 200 interior from the outside.Evacuation of or creation of a vacuum within the device 200 can be donethrough the outlet and valve 287. A vacuum pump, a venturi pump or otherevacuation device can be connected to the outlet and valve 287 toevacuate or create a vacuum within the device 200.

FIG. 3 shows a second embodiment of the extraction device. The device300 of FIG. 3 is designed for larger, commercial extraction batchesalthough it can also accommodate smaller batches, as desired. The device300 generally functions similarly to the devices 100 shown in FIGS.1A-1B with the addition of a condensing coil 315 to the solvent chamber310. After an extraction has been performed, the user heats thecollection reservoir 352 which volatilizes the solvent, separating itfrom the extracts. The gaseous solvent travels through the solventreturn 380 and into the condensing coil 315. The condensing coil 315sits in the outer tank 314 to which a cold bath has been added. As thegaseous solvent flows through the cool condensing coil 315 itrecondenses into a liquid phase that flows into the solvent reservoir312. The condensing coil 315 provides increased surface area for thethermal energy transfer from the gaseous solvent to the surrounding coolbath.

The condensing coil 315 of the device of FIG. 3 is disposed in thesolvent chamber 310. The condensing coil 315 is connected to and locatedabove the solvent reservoir 312 and connected to the solvent return 380at the inlet 386. The condensing coil 315 is constructed of materialhaving a high thermal conductivity, such as a metal or other suitablematerial. It is desirable that the coil is highly thermally conductiveto more quickly and efficiently condense the returning gaseous solventback into a liquid phase.

The outer tank 314 of the solvent chamber 310 extends vertically pastthe solvent reservoir 312 and around condensing coil 315, whichcompletely submerges the condensing coil 315 in the surrounding coldbath. Gaseous solvent, from the heated collection reservoir 352, entersthe condensing coil 315 from the return 380 through the inlet 386. Inthe condensing coil 315, thermal energy from the gaseous solvent istransferred to the surrounding cool bath. The large surface area of thecondensing coil 315, in contact with the cool bath, increases theconductive heat transfer which speeds condensation of the gaseoussolvent vapor into liquid solvent. The condensed solvent then flowsthrough the remainder of the condensing coil 315 where it dischargesinto the solvent reservoir 312.

A solvent inlet 316 is connected to the solvent reservoir 312 of theextraction device 300 of FIG. 3. The solvent inlet 316 is functionallysimilar to the solvent inlet 116 of the embodiments shown in FIGS.1A-1B. However, in the embodiment shown in FIG. 3, the solvent inlet 316rises higher from the top surface of the solvent reservoir 312 to ensurethat it rises above the level of the cold bath contained within theouter tank 314. Additionally, the solvent inlet 316 may function as avalve to release gas that may be trapped within the device 300.

The solvent reservoir 312 of the embodiment shown in FIG. 3 isconstructed in a similar manner and geometry as the solvent reservoir112 of the embodiment shown in FIGS. 1A-1B. As detailed above, thesolvent reservoir 312 has thin walls that allow for rapid thermal energytransfer across their cross-section, the rapid flow of thermal energyensuring that the solvent contained within the solvent reservoir 312maintains a sufficiently low energy state such that the solvent is keptin a liquid phase.

A view port 319 is disposed on the solvent reservoir 312, extendingthrough the outer tank 314 to the exterior of the device 300. The viewport 319 is similar to the view port 118 of the device 100 of FIGS. 1Aand 1B. The view port 319 is constructed of a transparent material setinto a metal housing and can include lighting elements, such as LEDs,used to illuminate the interior of the solvent reservoir 312. A user canobserve the interior of the solvent reservoir 312 through the view port319 to assess the amount of solvent within the tank and monitor thesolvent recovery process.

The outer tank 314 of the embodiment shown in FIG. 3 is constructed in asimilar manner, geometry and materials as the outer tank 114 detailed inthe embodiment shown in FIGS. 1A-1B. The sidewalls of the outer tank 314are necessarily higher than the tank 114, in order to contain the coldbath around not only the solvent reservoir 312 but the condensing coil315 as well.

The cold bath contained within the outer tank 314 should be of asufficiently low temperature to recondense the returning gaseoussolvent. The solvent used in the embodiment of FIG. 3 is butane, whichhas a boiling point of −1° C. The surrounding bath needs to be able tochill the gaseous solvent in solvent reservoir 312 and condensing coil315 to a temperature at least below the solvent boiling point in orderto recondense the solvent into a liquid phase. The dry ice and ethanolbath used in the embodiment of FIG. 3 has a temperature of approximately−78° C. This significant temperature difference from the boiling pointassists in recondensing the majority of the gaseous solvent to a liquidsolvent. Additionally, the large temperature variation between thesolvent reservoir 312 and the collection reservoir 352 helps drive therecycling of the solvent from the collection reservoir 352 and back intothe solvent reservoir 312.

Alternatively, a bath of dry ice pellets, ethanol and ethylene glycolmay be used. This alternate bath has a similar temperature but thetemperature may be controlled by varying the ratio of ethylene glycoland ethanol. The addition of the ethylene glycol raises the temperatureof the bath but still maintains it at a level to recondense the gaseoussolvent to its liquid state. The alternate bath also has the addedbenefit of maintaining its low temperature for a longer period of time.The ethylene glycol has a freezing point of −13° C., which is higherthan that of the dry ice. The ethylene glycol and ethanol form agel-like substance when mixed with the dry ice, this gel-like substancecan maintain a lower bath temperature for a longer period of time thanthe ethanol and dry ice bath. The cold bath increases the temperaturedifferential between the collection tank and the solvent tank, whichimproves the overall efficiency of the extraction process.

The solvent storage chamber 310 is connected to the extraction chamber330 via a connector 320. The connector 220 has a valve 322 and atransparent section 324 disposed therein. The valve 322 functionssimilarly to the valve 122 of the embodiment detailed in FIGS. 1A-1B,controlling and regulating the flow of the solvent from the solventreservoir 312 into the extraction chamber 330. The addition of thetransparent section 324 to the connector 320 allows a user to view theflow of solvent from the solvent reservoir 312 through the connector320. A user viewing the flow can determine if a greater or lesser flowrate is desirable and can adjust the valve 322, manually orelectronically, as needed. The solvent storage chamber 310 and theextraction chamber 330 may be permanently or releasably connected to theconnector 320. In the embodiment shown in FIG. 3, both chambers 310 and330 are releasably connected to the connector 320 using a sanitaryconnection.

The extraction chamber 330, as shown in the embodiment detailed in FIG.3, features the plant material chamber 332 having a top 334 and a bottom336. The plant material chamber 332 is surrounded by an outer tank orjacket 333 that contains a warm or hot bath. The jacket 333 may be asecond flexible or rigid tank that surrounds the plant material chamber332 or both may be integrated into a single unit. As shown in theembodiment of FIG. 3, the plant material chamber 332 features adouble-wall construction, similar to that found on insulated double-wallcoolers. The inner walls of the chamber 332 house the plant material andthe outer walls form the jacket 333. In this manner, the chamber 332 isattached and disposed in the center of the surrounding jacket 333.

A source of a warm/hot bath is connected to the jacket 333 through ports335 and 337. The source of the warm/hot bath may be controlled to anexact temperature, a temperature range, or just generally warm/hot,depending on the temperature gradient that is desired. The warm/hotbath, typically heated water, flows from a source (not shown) throughport 337, where it rises and surrounds the chamber 332 before exitingthrough port 335. In the embodiment shown, the chamber 332 isconstructed from a material capable of rapid thermal energy transferacross the sidewalls of the chamber 332. The rapid thermal energytransfer allows the heat from the surrounding warm/hot bath to penetratethe chamber walls and warm the material and solvent/solvent-extractsolution contained.

The plant material stored within the plant material chamber 332 iswarmed to assist in recovery of the solvent trapped within the plantmaterial after the extraction process has completed. By encircling thechamber 332 with the hot/warm jacket 333, the temperature of thematerial in the chamber 332 can be raised sufficiently high, after theextraction process, to volatilize remaining solvent. This gaseoussolvent can then be recovered for later use and/or storage.

The plant material chamber 332, as shown in the embodiment of FIG. 3,has solid sidewalls. View ports 339 a and 339 b are disposed about theperiphery of the plant material chamber 332 to allow the user to viewand observe the interior of the plant material chamber 332. The viewports 339 a and 339 b extend from the chamber 332 through thesurrounding bath and jacket 333. The view port 339 a is located at anupper portion of the plant material chamber 332 and the view port 339 bis located at a lower portion.

The view ports 339 a and 339 b allow the device 300 user to monitor andobserve the majority of the interior of the plant material chamber 332.Additionally, as in the solvent reservoir 312, the plant materialchamber may feature internal markings indicating the quantity of plantmaterial, solvent and/or other material stored within the plant materialchamber 332. Further, additional view ports may be installed on theplant material chamber 332 as necessary or as desired. The view ports339 a, 339 b and/or additional view ports may feature integrated lightsources, such as LEDs or other suitable lighting devices that illuminatethe plant material chamber 332 interior. Alternatively, the plantmaterial chamber 332 may be constructed of a thermally conductivetransparent material that would allow a user to view the internalcontents of the plant material chamber 332 through the surroundinghot/warm bath in the jacket 333.

The top 334 and/or bottom 336 of the plant material chamber 332 may bereleasably or permanently affixed to the chamber 332. In the embodimentshown in FIG. 3, the top 334 and/or bottom 336 is releasably affixed tothe plant material chamber 332 using a sanitary connection such as ahinged clamp. In the embodiment of FIG. 3, a user may access theinterior of the plant material chamber 332 through the top 334 and/orthe bottom 336, both of which are open ring-like structures. Theextraction chamber 330 may be removed from the device 300, the top 334or bottom 336 may then be removed from the chamber 332 to allow a usergreater access to the interior of the chamber 332. Access to the chamberis required for the user to place the material containing theextractable compound(s) within it. The plant material chamber 332 withthe top 334 and bottom 336 in place are sealed and house the material,solvent, and solvent-extract solution. Alternatively, instead of havinga removable top 334 or bottom 336, a sealable access may be disposed onone or both surfaces. The access provides a way for a user to access theinterior of the plant material chamber 332, such as by an access door,for example.

The plant material chamber 332 or the bottom 336 can include a filterthat prevents solid material housed within the extraction chamber 332from passing through the connector 340 and entering the collectionreservoir 352. Alternatively, the filter may be disposed in anintervening structure between the extraction chamber 330 and thecollection chamber 350. The filter could include a mesh screen, a paperfilter or a semi-permeable membrane through with the solvent-extractsolution may pass.

The extraction chamber 330 is connected to the collection chamber 350via a connector 340. The extraction chamber 330 may be permanently orreleasably connected to the connector 340. The connector 340 has a valve342 and a transparent section 344 disposed therein. The valve 342functions similarly to the valve 122 of the embodiments detailed inFIGS. 1A-1B, regulating and controlling the flow of the solvent-extractsolution from the plant material chamber 332 into the collection chamber350. The addition of the transparent section 344 to the connector 340allows a user to view the flow of the solvent-extract solution from theplant material chamber 332 through the connector 340. A user viewing theflow can determine if a greater or lesser flow rate is desirable and canadjust the valve 342, manually or electronically, as needed. Theextraction chamber 330 and the collection chamber 350 may be permanentlyor releasably connected to the connector 340. In the embodiment shown inFIG. 3, both chambers 330 and 350 are releasably connected to theconnector. 340 by a sanitary connection.

The collection chamber 350 of the embodiment shown in FIG. 3 has acollection reservoir 352, a hot/warm bath jacket 354 having ports 353and 355, an access 357, the access having a view port, and a solventreturn outlet 384.

As with the collection reservoir 152 of the embodiments shown in FIGS.1A-1B, the collection reservoir 352 of the embodiment shown in FIG. 3 isconstructed having similar geometry and material properties. As with theprevious embodiment, the collection reservoir 352 is surrounded by a hotbath. In the embodiment shown in FIG. 3, the collection reservoir 352 issurrounded by a jacket 354, which contains the hot bath around thereservoir 352. The jacket 354 and the reservoir 352 are a single unit,constructed as a double-wall vessel, similar in manner to that found ininsulated double-wall coolers. The inner walls of the unit form thereservoir 352 and the outer walls form the jacket 354. The space betweenthe walls houses the hot/warm bath. The jacket 354 features ports 353and 355, through which the hot/warm bath is introduced, dischargedand/or recirculated. The ports 353 and 355 are connected to a hot/warmbath source that heats a medium. In this embodiment, the medium is waterthat is then pumped or fed through one of the ports.

The heated medium fills the space between the jacket 354 and thecollection reservoir 352. The heated medium may be sealed in the jacket354 until the extraction is done, then drained through a port.Alternatively, the heated medium can be continuously introduced througha port and discharged continuously through the other port, ensuring thata fresh supply of heated medium surrounds the collection reservoir 352and ensuring the collection reservoir 352 and the solvent-extractsolution stored within is kept at an ideal temperature or range oftemperatures. The source of the hot/warm bath may be connected to thedischarge port such that the hot/warm bath is constantly recirculatingthrough the jacket 354, returning to the source to be reheated andrecirculated. This is the method used in the embodiment as shown in FIG.3, which may include an internal heater disposed within the jacket 354that further heats or maintains the temperature of the surroundinghot/warm bath, as necessary.

In another embodiment, the heated medium may be pumped into the jacket354 and left there, a separate heater disposed within the jacketmaintaining the desired temperature of the medium. In anotherembodiment, the jacket 354 may be filled with a medium that may beheated by an internal or external source. The jacket can be filled withthe heated medium prior to or during an extraction cycle. Once theextraction cycle(s) is completed, the medium is allowed to cool and isthen reheated during the next extraction cycle(s). The medium may besealed within the jacket 354 permanently and heated as necessary, or maybe replaceable or replenished as needed through port(s) disposed on thejacket that allow for changing the medium or adding additional medium.

In the embodiment shown in FIG. 3, the connector 340 extends through thetop surface of the collection reservoir 352. The connector 340 extendsinto the interior of the collection reservoir 352, with the end of theconnector 340 located at a point below the outlet 384. The extension ofthe connector 340 helps to prevent solvent-extract solution from beingdrawn through the outlet 384 and helps prevent solvent vapor fromtraveling into the plant material chamber 332. Since the system issealed, as the solvent is dispensed from the solvent reservoir 312, thereturn 380 can act as a siphon if the valve 382 is open. The siphoneffect could potentially draw the solvent-extract solution through theoutlet 384 and up the return 380. Also, the solvent vapor islight-weight and has a tendency to rise to the top of the reservoir 352.By terminating the connector 340 below the outlet 384, solvent vapor isless likely to travel back through the connector 340. This is especiallytrue when the level of the solvent-extract solution is above thetermination point of the connector 340. This forms a liquid barrier tothe solvent vapors traveling back through the connector 340 and up thevarious sections and connections of the device 300.

The access 357 of the embodiment shown in FIG. 3 allows a user to accessthe contents of the collection reservoir 352. The access 357 is sealedby a cap that prevents contaminants from entering the solvent-extract orextract solution stored within the collection reservoir 352. Othersuitable releasable options for sealing the access 357 exist and may beused. The cap sealing the access 357 may also feature a view port toallow the user to observe and/or monitor the contents and activitywithin the reservoir 352. Further, this view port may feature thelighting feature as discussed above to further enhance a user's viewinto the reservoir. Additionally, the interior of the collectionreservoir 352 may feature markings or indications to indicate the filllevel or other features of the solution or materials within thecollection reservoir 352.

A pressure indicator, such as the pressure gauge 170 of the embodimentshown in FIGS. 1A-1B, may be disposed on the collection chamber 350although it is not shown in FIG. 3. The indicator may be disposed on theupper surface of the reservoir 352 or on the cap that seals the access357. Alternatively, the indicator may be disposed on the jacket 354 maybe in fluid communication with the collection reservoir 352 in order tosense and display the internal pressure of the device 300. Furtherembodiments include an electronic pressure sensor that transmits andindicates a pressure on a display located externally of the device.

The solvent return 380 is a path for the solvent vapors to travel fromthe reservoir 352 to the condensing coil 315. As the solvent extractsolution is heated in the reservoir tank 352, the solvent volatilizesinto a gaseous phase. In the gaseous phase, the solvent can flow throughthe outlet 384, through the return 380 and into the condensing coil 315through the inlet 386. The return 380 has a valve 382 and a transparentsection 383 disposed therein. The valve 382 regulates the flow ofsolvent vapors through the return 380. The valve 382 may be controlledmanually or electronically by a user or a controller. The transparentsection 383 allows a user to observe the flow of the solvent vaporsthrough the return 380, which may be desirable or necessary in order todetermine the regulation of the vapor through the valve 382.

The solvent return may also include an oxygen purge element. In theembodiment shown in FIG. 3, the purge is a valve 388 disposed on thereturn 380. The valve 388 allows the user to purge or decrease theamount of oxygen within the device 300 before starting an extractionprocess and/or loading the solvent. When using a combustible orflammable solvent, the purging of oxygen from the system assists inlowering the risk of solvent ignition. The valve 388 may be a one-wayvalve or may be actuated by a user or other control means. The purge ofoxygen or other atmosphere within the device may be accomplished byintroducing a secondary, inert gas that displaces the existing gaswithin the device 300 through the valve 388. Alternatively, a vacuum canbe created within the device, the evacuated air being drawn through thevalve 388 by a mechanical means. By creating a vacuum or low pressurewithin the device, the amount of oxygen within the device is preferablybelow the level required for ignition and/or combustion of the solvent.

Additionally, the return 380 as shown in the embodiment of FIG. 3 alsoincludes a support 387 that contacts the base/ground 360. The support387 is a stand that stabilizes the return 380. The return 380 may beconnected to sections of the device to provide additional stability andstructure to the device as necessary. In the embodiment shown in FIG. 3,the return 380 is connected to the solvent storage chamber 310 to assistwith stabilizing that section. The return 380 of this embodiment istherefore made of a structural material such as metallic pipe or othersuitable material that can withstand the forces required to providesupport to the device 300.

The embodiment of the device 300 of FIG. 3 may be scaled larger orsmaller as necessary depending on the size of the extraction batches auser intends to run. All the sections can be made requisitely smaller orlarger depending on the anticipated user needs. The materials used forconstructing the device 300 should be at least non-reactive with thesolvent, plant material and the extracted compounds. Preferably, thematerials used are of food and/or medical grade quality, but othersuitable materials can be used. Additionally, sanitary connections arepreferably used throughout the device 300 for all releasableconnections. However, other suitable releasable connections can be used,such as threaded connections.

The chambers 310, 330 and 350, the connectors 320 and 340 and the return380 of the device 300 of FIG. 3 are releasably connected using variousreleasable fittings and connection means. This allows the varioussections to be removed, stored, serviced, replaced, sold separately,maintained and cleaned individually as necessary.

A pump may be used to extract, move and recompress the gaseous solventfrom the collection reservoir 352 into the solvent reservoir 312. Thepump would need to be suitable for moving the gaseous solvent, i.e.,fire rated to minimize the potential for explosions and food safe so asto not contaminate the recovered solvent. For example, the extractionsystems can include a hydrocarbon-rated pump that does not exceed 100psi and can be placed in-line with the return and/or could access any ofthe device chamber(s) to aid in the extraction process. The pump couldbe added to the disclosed system or could replace the return 380 andminimize or eliminate the need for the baths and the condensing coil315.

The pump creates low pressure in the collection reservoir causing thesolvent to boil off from the solvent-extract solution due to the lowvapor pressure within the collection reservoir 352. The gaseous solventwould then be pumped into the solvent reservoir 312 under pressure. Theincreased pressure would cause the gaseous solvent to recondense into aliquid phase. Alternatively, the cold bath about the solvent reservoir312 could be used to assist in the recondensing of the gaseous solvent,lessening the pressure required from the pump. A hot/warm bath may alsobe utilized to assist with the separation of the solvent from thesolvent-extract solution.

FIG. 4 is a further embodiment of an extraction device 400, the device400 including a refinement chamber 460 disposed between the extractionchamber 430 and the collection chamber 450.

The device 400 includes a solvent chamber 410, a connector 420, anextraction chamber 430, a connector 440, a refinement chamber 460, acollection chamber 450 and a solvent return 480. The device 400 of FIG.4 is substantially the device 200 of FIG. 2A with the addition of therefinement chamber 460.

A solvent chamber 410 includes a solvent reservoir 412, an outer wall414 spaced a distance 413 from the reservoir 412, a shared base 415 anda view port 418. Optionally, the solvent chamber can include a pressuregauge 411 and a solvent inlet (not shown). The pressure gauge 411 canindicate a positive pressure, a negative pressure or a combinationthereof.

The solvent reservoir 412 contains the liquid solvent and is surroundedby an outer wall 414 spaced a gap 413 away. The gap 413 can be filledwith a temperature bath to heat or preferably cool the solvent reservoir412 to assist with the recovery of the solvent used during theextraction process. A drain 417 is included on the shared base 415 toassist with draining the temperature bath from between the outer wall414 and the solvent reservoir 412.

The solvent reservoir is connected to and in fluid communication withthe connector 420. The connector 420 includes a sanitary valve 422 and asanitary cap 424. As in the device 200 of FIG. 2A, a solvent return 228can be affixed to the sanitary cap 424. The solvent return allowingfluid communication between the solvent reservoir 412 and the plantmaterial chamber 432.

The extraction chamber 430 includes a plant material chamber 432,surrounded by an outer wall 438 set a distance 439 from the chamber 432and a shared base 437. The plant material chamber 432 includes anaffixed or integrated top sanitary ferrule 434. The sanitary ferrule 434interfaces with the sanitary cap 424 to form a sanitary connection whenthe chamfered circumferences of each are compressed using a clamp suchas a single pin-hinged clamp.

The gap 439 between the outer wall 438 and the plant material chamber432 can be filled with a temperature bath. Preferably the gap 439 isfilled with a hot or warm water bath after the extraction is complete.The heating of the solvent-ladened plant material within the plantmaterial chamber 432 volatilizes the entrapped solvent so that it may berecovered for later extraction processes. A drain outlet 435 is includedto drain the temperature bath from the gap 439.

A bottom sanitary ferrule 436 is affixed or integrated to the sharedbase 437. The bottom sanitary ferrule 436 can include a filter designedto exclude or prevent plant material from the plant material chamber 432from traveling through the remainder of the device 400.

A connector 440 connects and facilitates fluid communication between theextraction chamber 430 and the refinement chamber 460. The connector 440includes a sanitary valve 442, a top sanitary cap 444 and a bottomsanitary cap 446. The top sanitary cap 444 interfaces with the bottomsanitary ferrule 436 to form a sanitary connection that can be clampedtogether about the periphery of the chamfered circumferences of thepieces 444 and 436.

The bottom sanitary cap 446 of the connector 440 interfaces with the topsanitary ferrule 466 of the refinement chamber 460. As discussed above,the interfacing of the sanitary cap 440 and sanitary ferrule 446 forms asanitary connection linking the connector 440 and the refinement chamber460.

The refinement chamber 460 includes a refinement reservoir 462, an outerwall 464 spaced a distance 463 about the reservoir 462, a top 465 and abase 467, and bottom sanitary ferrule 468.

The gap 463 is preferably filled with a cold temperature bath. Theextract-rich solvent solution is transferred from the extraction chamber430 through the connector 440 and into the refinement chamber 460. Thecold refinement chamber solidifies impurities such as waxes that wereextracted from the plant material, the solidified impurities can then befiltered from the extract. The cold temperature can also thicken theheavier or denser extracted oils, which may not be desirable in thefinal product. These thickened oils can also be filtered from theextract solution. Additionally, the extract-rich solvent solution cansit in residence for a set amount of time within the refinementreservoir 462. The residence time within the reservoir 462 can allowimpurities to settle out from the solution, the refined solution canthen be transferred into the collection chamber 450.

A filter can be placed within the bottom sanitary ferrule 468. Thefilter can be designed to remove solids, such as waxes, and/or filterheavier oil components from the extract-rich solvent solution. The waxesand/or oils can be recovered from the filter and used in othercommercial products or processes.

Once the extract-rich solvent solution is sufficiently refined in therefinement chamber 460, the solution is transferred into the collectionchamber 450 through the sanitary ferrule 456 disposed atop thecollection reservoir 452.

The collection chamber 450 includes a collection reservoir 452, an outertank 454 and an extract outlet 455. A hot or warm temperature bath isconstrained about the collection reservoir 452 by the outer tank 454,heating the extract-rich solvent solution within the reservoir 452. Thesolvent is volatilized and travels through the solvent return 480 intothe solvent reservoir 412 where it recondensed into liquid solvent thatcan be used for other extractions.

An inclined floor 453 can be included in the collection reservoir 452 toassist with the collection of the extract through the outlet 455. Theinclined floor 453 can be placed in or integrated with the collectionreservoir 452. Alternatively, the collection reservoir 452 can beconstructed with a sloped base.

A drain outlet 458 is disposed on the outer tank 454 to assist withdraining the enclosed temperature bath.

A pressure indicator 470, similar to the pressure indicator 170 of FIGS.1A and 1B, is in fluid communication with the interior of the collectionreservoir 452. The pressure indicator 470 allows a user to observe andmonitor the interior pressure of the collection reservoir 452.

The solvent return 480 is connected to the collection reservoir 452 atan inlet 484. In the embodiment shown in FIG. 4, the solvent return 480is substantially the same as the solvent return 280 of FIG. 2A. Thesolvent return 480 includes a conduit extension piece 483 that isinserted in the return 480, lengthening the return 480 to account forthe addition of the refinement chamber 460. The conduit extension piece483 is connected to the main conduit 485 using a sanitary connection487.

The various connections, 487 and 488, along the length of the solventreturn 480 are accomplished using suitable sanitary connections. The useof sanitary connections throughout the device 400 assists in ensuringthe purity of the extract.

The solvent return 480 includes a sanitary valve 482 that is used tocontrol and regulate the flow of the volatilized solvent through thereturn 480.

The solvent return includes an outlet 486 that terminates in the solventreservoir 412. The outlet 486 is positioned above the level of theliquid solvent within the reservoir 412. As the volatilized solventexits the outlet 486, it is recondensed into liquid solvent. Theelevated position of the outlet assists in preventing liquid solventfrom flowing back down the return 480.

Extraction Process

The devices 100 and 200, disclosed above, are designed to performclosed-system plant extraction process and are discussed now using thedevice shown in FIG. 1 as an example. Plant material is placed in thedevice, which is then sealed. The extraction and recovery processes arethen run, resulting in end products of recovered solvent and extractedplant compounds.

Prior to operating the device 100 or adding solvent to the solventreservoir 112, any oxygen within the device 100 should be minimized orremoved. This can be done by pulling a vacuum within the device throughan external port such as valve 188. A user can check the pressure gauge170 to observe when the device 100 has been evacuated. The devices canalso include a vacuum gauge, not shown, in some examples to measure thevacuum level within the device. Alternative oxygen removal options canbe used, such as the use of oxygen scavenging chemicals or sacrificialoxygen removal elements disposed within the device 100.

The solvent is disposed within the solvent reservoir 112, where it ismaintained in a liquid phase due to the vapor pressure created by thesolvent. Alternatively, the reservoir 112 may be chilled to assist inkeeping the solvent in a liquid phase. Solvent is then released from thesolvent reservoir 112 by the valve 120, the solvent then flows into theextraction chamber 132.

In the extraction chamber 132, the solvent contacts the material havingextractable compound(s). The solvent flows over the material picking upand washing away the extractable compound(s), the solvent andextractables forming a solvent-extract solution. The residence time ofthe solvent on the material may be adjusted by varying the entry andexit flow rates of the valves 120 and 140 leading into and out of theextraction chamber 132.

The solvent-extract solution enters the collection reservoir 152 throughthe valve 140. Once the extraction is completed, the collectionreservoir 152 is surrounded by a hot bath that heats the solvent-extractsolution within the reservoir. It is desirable that the temperature ofthe bath is high enough to volatilize the solvent relatively easily, butlow enough so as to not affect the extract(s).

Alternatively, during the extraction process, the collection reservoir152 can be heated and the solvent reservoir 112 cooled. The solvent isdispensed from the solvent reservoir 112 and flows through the plantmaterial in the plant material chamber 132. The solvent-extract solutionthen flows into the collection reservoir 152 where the solventvolatilizes. The gaseous solvent travels through the solvent return 180and recondenses in the solvent reservoir 112. From there, the solventmay be recirculated through the extraction device 100 repeatedly. Thisalternative process performs a continuous recirculating extraction loopacross the contained material.

As the solvent is heated by the hot bath, it undergoes a phase changefrom a liquid to a gas. In the gaseous phase, the solvent can flowthrough the outlet 184, up the solvent return 180, into the inlet 186and finally recondenses in the cold solvent reservoir 112. The recyclingof the solvent conserves the solvent for repeated cycles during theextraction process or for later use. By relying on the phase changeproperties of the solvent, no pumps or other mechanisms are required tomove solvent through the device although a food-safe pump could beincluded as discussed above. As discussed above, a pump, rated for thesolvent used and made of food safe materials, could be added to thedevice 100 to assist with and/or move the solvent from the collectionreservoir 152 to the solvent reservoir 112.

Since the solvent is driven off of the solvent-extract solution due toheating of the solution within the collection reservoir 152, theremaining extract is left partially or completely purified. Once theextraction process is completed and all of the solvent-extract solutionhas collected in the collection reservoir 152, the hot bath ismaintained to further volatilize the solvent. The solvent vapors aredrawn up the solvent return 180, leaving behind purified product in thecollection reservoir 152. The product may need further refining whichcan be performed by various means.

Extraction of Canabinoids

The device may be used to extract cannabinoids from marijuana plantmaterial to form an oil or extract solution rich in cannabinoids, forexample. The extraction process described below uses the deviceembodiment as shown in FIG. 2, however, it is understood that theprocess can be performed using other embodiments of the device asdescribed herein. Other plant materials can be used with the disclosedextraction devices as well.

A user first removes or minimizes any oxygen within the device 200 orsolvent reservoir 212 by evacuating the device 200 or solvent reservoir212. The device 200 or solvent reservoir 212 can be evacuated by avacuum or venturi pump that is connected to an external valve of thedevice, such as valves 285 or 287. Oxygen and other gases should beremoved from the device 200 or solvent reservoir 212 for safety andefficiency. The removal of the oxygen will reduce the likelihood ofcombustion or explosion of the butane as the device 200 or solventreservoir 212 is filled. Remaining oxygen and other gasses will alsodisplace the butane as it is introduced to the device, which can causethe device 200 or solvent reservoir 212 to fill improperly orinefficiently.

The user then adds solvent to the solvent reservoir 212 of the solventchamber 210. For the process described here, the solvent used is butane,preferably a food-grade, refined version of n-butane or isobutane.

To load the plant material into the plant material chamber 232, the userunclamps the sanitary connections between the sanitary cap 224 and topsanitary ferrule 234 and the bottom sanitary ferrule 236 and sanitarycap 244. The extraction chamber 230 can then be removed from the device200. With the inner cavity of the plant material chamber 232 exposed,the user begins loading the material inside. The use of an extractionprocess allows cannabinoids to be obtained from parts of the plant oftendiscarded such as the leaves and stems as well as the traditional buds.The plant material is packed into the plant material chamber 232 and theextraction chamber 230 is remounted into the device 200. The extractionchamber 230 is secured within the device 200 by clamping the sanitarycap 224 and top sanitary ferrule 234 and clamping the bottom sanitaryferrule 236 and sanitary cap 244. When clamping the bottom sanitaryferrule 236 and sanitary cap 244, the filter gasket can be insertedeither between the two or within the plant material chamber 232.

Once the extraction chamber 230 is replaced within the device 200, thedevice 200 will need to be evacuated to remove oxygen. If the device 200was previously evacuated before adding the solvent, the removal of theextraction chamber 230 will have exposed the interior of the device 200to oxygen once again. The device 200 can be evacuated through one of theexternal valves, such as valve 285 or 287, by connecting a vacuum pump,venturi pump, or other suitable evacuation device. Once the device 200has been suitably evacuated, this can be confirmed by the pressureindicator 270, the extraction process can begin.

To initiate the extraction process, the valve 220 is opened to allow thebutane to flow from the solvent reservoir 212 and into the plantmaterial chamber 232. Once the butane has flowed from the solventreservoir 212 and into the plant material chamber 232, the valve 222 isleft open to account for liquid expansion of the butane solvent. Thebutane then sits on the plant material extracting the cannabinoids.After a set amount of time or once the user observes the extractionprocess is complete through a view port, the solvent-extract solution isreleased from the plant material chamber 232 through the valve 240 andinto the collection reservoir 252.

Once the extraction process has been completed and most of thesolvent-extract solution has drained into the collection reservoir 252,the valve 222 is closed and a hot/warm bath is applied to the plantmaterial chamber 232 using the jacket 233. A bath source is connected tothe inlet 237 and the outlet 235. The source could be simply a hot watertap or a water heating and recirculation unit. If using a hot water tap,the tap is connected via a line to the inlet 237 and the outlet isconnected to a line that runs to a drain. If using aheating/recirculating unit, the inlet and outlet are run to the unit sothat the hot/warm bath may be continuously heated and distributedthrough the jacket 233. The hot/warm bath about the plant materialchamber 232 volatilizes remaining solvent so that it may be recoveredthrough the collection reservoir 252.

The hot/warm bath source is connected to jacket 254 of the collectionchamber 250. The source of the bath may be the same or different thanthe source of the bath used in the extraction chamber. It may bedesirable for the bath surrounding the collection chamber 250 to be ahigher temperature than the temperature of the bath surrounding theextraction section in order to volatilize the butane faster and/or moreefficiently.

Alternatively, the baths of the extraction chamber 230 and thecollection chamber 250 may share the same source, aheating/recirculating unit, the source heating water to a temperaturedesired for the collection chamber 250. The bath has an initialtemperature when it enters the jacket 254 of the collection chamber 250through the inlet 258 a. The water then fills and surrounds thereservoir 252, imparting thermal energy to the reservoir 252 and thechamber 250. The water finally exits the port 258 b at a secondtemperature. The upper jacket outlet 258 b of the collection chamber 250is connected to the jacket inlet 233 a of the extraction chamber 230.The bath could flow from the jacket of the collection chamber 250 intothe jacket of the extraction chamber 230 at the second temperature. Thebath then circulates through the gap 239 of the extraction chamber 230,imparting thermal energy to the extraction chamber 230, the plantmaterial chamber 232 and the enclosed plant material, before exitingthrough port 233 b. After exiting port 233 b, the bath can be returnedto a heating/recirculation unit, where the water is reheated and againpumped through the jackets 254 and gap 239. Alternatively, the bath canbe discarded after exiting port 233 b, with new, heated bath fluidintroduced through the inlet 258 a.

Once a user has observed or believes the majority of the trapped solventin the plant material chamber has been volatilized and has flowed intothe collection reservoir 252, the valve 222 is closed. Thesolvent-extract solution, now in the collection reservoir 252, is warmedby the surrounding hot/warm bath contained in the jacket 254. As thesolution heats, the butane boils and undergoes a phase change into agaseous state. The butane gas then flows to the outlet sanitary ferrule284 and into the solvent return 280, through which it rises. The gasexits the solvent return 280 through the outlet 286, directly into thesolvent reservoir 212, to be recovered. Alternatively, the solvent canreturn through a condensing coil 315, as shown in FIG. 3, to be cooledfor recovery. As the gas flows through the coil, the surrounding coldbath, contained by the outer tank 214, causes the butane gas to condenseback into a liquid phase. The mostly liquid butane re-enters the solventreservoir 212, where it can then be held for later extraction use or fedback through the device 200.

The extraction process using the device 200 may be a circulatory processin which the butane flows through the cascaded sections as a liquid andreturns to the top as a gas where it recondenses back into a liquid.Such a process conserves the butane solvent and allows for the recoveryof it for use in later extractions or for other purposes.

As the hot/warm bath is being applied to the solvent-extract solution inthe reservoir 252, the user is chilling the solvent reservoir 212 andcondensing coil 315. The solvent reservoir 212 and condensing coil 315are chilled by a surrounding cold bath composed of liquid alcohol anddry ice pellets. This cooling of the solvent reservoir 212 andcondensing coil 315 assists in drawing the gaseous solvent through thesolvent return 280 so that it may be condensed and stored within thesolvent reservoir 212.

The extract remaining in the collection reservoir 252 is rich incannabinoid extracts and may be further refined externally or internallyof the device as necessary or desired. External refinement may includeplacing the solution under a vacuum to further remove any remainingbutane. Other refinement techniques exist and are known and may be usedto refine the extracted material.

Other plant material may be used to extract other desired compounds,such as but not limited to, essential oils.

Additionally, to perform the extraction, other solvents may be used,such as other hydrocarbons, refrigerants such as R-134a, and alcohols,as long as they are in ratios that do not exceed the operationalpressure specifications of the device as set forth by the manufacturer.The selected solvent should extract the desired compounds from thematerial and have a boiling point below that of the extracted materialso that the solvent may be separated by heating the resultingsolvent-extract solution. The properties of the selected solventdetermine the temperature gradient required to cycle the solvent throughthe device. The temperature gradient sets the temperatures of the cooland hot/warm baths.

Purification of Butane

The device may also be used to refine butane to a higher purity withoutthe plant material present. The butane is disposed in the device as inthe other examples, in the solvent storage tank 212. The butane is thendispersed through the plant material chamber 230 and into the collectionreservoir 252 even though no plant material extraction occurs during thebutane purification process. Alternatively, a direct connection betweenthe solvent storage chamber 210 and the collection chamber 250 may beused in this case, thus bypassing the need to insert the extractionchamber 230 into the device 200. Once the butane has collected in thecollection reservoir 252, it is heated and volatilized by thesurrounding hot/warm bath. Simultaneously, the user chills the solventstorage chamber 210 using a cold bath. The now gaseous butane flows fromthe collection reservoir 252, through the return 280 and into thesolvent storage section 210. As the gaseous solvent contacts thenow-chilled solvent storage chamber 210, it begins to condense in thecoil 215. The resulting purified liquid solvent is then captured in thesolvent storage tank 212.

Butane, as with many substances, has a specific boiling point. In thecase of butane, the boiling point is a range of ˜2° C. Having such anarrow boiling point, it is possible, through careful temperaturecontrol of the bath surrounding the collection reservoir 252, to holdthe butane at the critical boiling temperature, thus ensuring that theemanating gaseous vapors are predominately gaseous butane. Bycirculating the butane through the device repeatedly, the butane refinesand becomes purer. The remaining materials left in the collectionreservoir 252 after the purification has completed are miscellaneoushydrocarbons and other pollutants that were left in the butane duringthe manufacturing process. The user is left with high-purity liquidbutane in the inner tank 212. This purified butane can then be used torun extraction processes or can be sold commercially.

The features disclosed in the foregoing description, or the followingclaims, or the accompanying drawings, expressed in their specific formsor in terms of a means for performing the disclosed function, or amethod or process for attaining the disclosed result, as appropriate,may, separately, or in any combination of such features, be used forrealizing the invention in diverse forms thereof.

1. A cannabinoid extraction device, comprising: a solvent chamber havinga solvent chamber return inlet, the solvent chamber structured to storea solvent having a stored solvent volume; a solvent chamber-cannabinoidcontaining plant material chamber interface having a first side and anopposing second side, the first surface attached to the solvent chamberand structured to receive solvent released from the solvent chamber; acannabinoid containing plant material chamber attached to the secondside of the solvent chamber-cannabinoid containing plant materialchamber interface, the cannabinoid containing plant material chamber influid communication with the solvent chamber and structured to receivethe solvent released from the solvent chamber, the cannabinoidcontaining plant material chamber structured to house cannabinoidcontaining plant material and to expose the received solvent to thecannabinoid containing plant material to produce a cannabinoidcontaining solvent-extract solution; a cannabinoid containing plantmaterial chamber-collection chamber interface having a first side and anopposing second side, the first side attached to the cannabinoidcontaining plant material chamber and structured to receive thesolvent-extract solution from the plant material chamber; a collectionchamber attached to the second side of the cannabinoid containing plantmaterial chamber-collection chamber interface, the collection chamber influid communication with the cannabinoid containing plant materialchamber and structured to receive the cannabinoid containingsolvent-extract solution from the cannabinoid containing plant materialchamber, the cannabinoid containing solvent-extract solution includingat least a cannabinoid produced from the exposure of the solvent to thecannabinoid containing plant material; a collection chamber-solventreturn interface having a first side and a second side, the first sideof the collection chamber-solvent return connector attached to thecollection chamber and structured to receive the solvent in a gaseousform; and a solvent return attached between the second side of thecollection chamber-solvent return interface and the solvent chamberreturn inlet, the solvent return structured to provide fluidcommunication between the collection chamber and the solvent chamber andto provide a pathway for the gaseous solvent to return to the solventchamber, wherein the solvent return comprises flow control featuresincluding at least one of a flow regulating valve, a purge valve, or acombination thereof; and wherein the solvent chamber, the cannabinoidcontaining plant material chamber, the collection chamber, and thesolvent return form a sealed, closed-cycle fluid pathway.
 2. Thecannabinoid extraction device of claim 1, wherein the cannabinoidcontaining plant material chamber is disposed vertically below thesolvent chamber and the collection chamber is disposed vertically belowthe cannabinoid containing plant material chamber.
 3. The cannabinoidextraction device of claim 1, further comprising a solvent chamberhousing that surrounds sidewalls of the solvent chamber and is spacedapart from the sidewalls of the solvent chamber.
 4. The cannabinoidextraction device of claim 3, wherein the solvent chamber housing alsoextends across a bottom surface of the solvent chamber and is spacedapart the bottom surface of the solvent chamber.
 5. The cannabinoidextraction device of claim 3, further comprising a cold bath housed inthe solvent chamber housing, and wherein the cold bath causes thesolvent chamber to become colder than the collection chamber, whichcreates a temperature gradient between the solvent chamber and thecollection chamber, and wherein a temperature of the cold bath is belowa boiling point of the solvent.
 6. The cannabinoid extraction device ofclaim 3, further comprising a cold bath housed in the solvent chamberhousing, and wherein the cold bath includes dry ice pellets andethyl-alcohol.
 7. The cannabinoid extraction device of claim 3, furthercomprising at least one drain in the solvent chamber housing.
 8. Thecannabinoid extraction device of claim 1, further comprising a solventport providing a fluid pathway to the solvent chamber.
 9. Thecannabinoid extraction device of claim 1, further comprising acannabinoid containing plant material chamber jacket that surrounds atleast a portion of the cannabinoid containing plant material chamber.10. The cannabinoid extraction device of claim 1, further comprising acollection chamber housing that surrounds sidewalls of the collectionchamber and is spaced apart from the sidewalls of the collectionchamber.
 11. The cannabinoid extraction device of claim 10, wherein thecollection chamber housing also extends across a bottom surface of thecollection chamber and spaces apart the bottom surface from thecollection chamber housing.
 12. The cannabinoid extraction device ofclaim 10, further comprising at least one drain in the collectionchamber housing.
 13. The cannabinoid extraction device of claim 1,wherein the solvent return is rigid or partially rigid.
 14. Thecannabinoid extraction device of claim 1, further comprising a controlvalve positioned to regulate flow of the gaseous solvent from thecollection chamber into the solvent return.
 15. The cannabinoidextraction device of claim 1, further comprising a purge valvestructured to selectively release at least one of oxygen and otherfluids or gases from the solvent return at a predetermined thresholdpressure.
 16. The cannabinoid extraction device of claim 1, wherein oneor more of the solvent chamber, the cannabinoid containing plantmaterial chamber, and the collection chamber have one or more of a viewport, an internal pressure gauge, a thermometer, and a volume indicator.17. The cannabinoid extraction device of claim 1, wherein solventchamber-cannabinoid containing plant material chamber interface includesat least one sanitary fitting, and wherein one or more of the solventchamber, the cannabinoid containing plant material chamber, thecollection chamber, and the solvent return include stainless steel. 18.The cannabinoid extraction device of claim 1, further comprising acondensing coil positioned between the solvent return and the solventchamber return port, the condensing coil configured to cool the solventas the solvent travels through the condensing coil, and furtherpositioned to dispense the cooled solvent in the solvent chamber throughthe solvent chamber return port.
 19. The cannabinoid extraction deviceof claim 1, wherein the solvent chamber stores the solvent and thesolvent is one or more of butane, a hydrocarbon-based solvent other thanbutane, a refrigerant-based solvent, and an alcohol-based solvent. 20.The cannabinoid extraction device of claim 1, further comprising arefinement chamber attached between the cannabinoid containing plantmaterial chamber and the collection chamber, the refinement chamberconfigured to receive the cannabinoid containing solvent-extractsolution from the cannabinoid containing plant material chamber, exposethe cannabinoid containing solvent-extract solution to a refinementsolvent to produce a refined cannabinoid containing solvent-extractsolution, and dispense the refined cannabinoid containingsolvent-extract solution to the collection chamber.
 21. The cannabinoidextraction device of claim 1, wherein at least one of the solventchamber-cannabinoid containing plant material chamber interface, and thecannabinoid containing plant material chamber-collection chamberinterface includes a sanitary connector.
 22. The cannabinoid extractiondevice of claim 1, wherein the solvent return is connected to thecollection chamber by at least one of a threaded connection and a quickrelease connector.
 23. The cannabinoid extraction device of claim 1,wherein the solvent return includes a valve structured to regulate fluidflow through the solvent return, and wherein the solvent return furthercomprises a rigid solvent return and a partially rigid solvent returnthat includes a flexible hose, the partially rigid solvent returnpositioned in parallel with the rigid solvent return, the valvestructured to control the flow of gaseous solvent from the collectionchamber into one or the other of the rigid or the partially rigidsolvent return.
 24. The cannabinoid extraction device of claim 1,further comprising a pump disposed in one or both of in-line with thesolvent return and at a position to access any one or more of thesolvent chamber, the cannabinoid containing plant material chamber, thecollection chamber, and the solvent return.
 25. The cannabinoidextraction device of claim 1, further comprising at least one filter influid communication with one or more of the cannabinoid containing plantmaterial chamber, the cannabinoid containing plant materialchamber-collection chamber interface, and the collection chamber, thefilter structured to prevent passage of one or more compounds into thecollection chamber.
 26. A cannabinoid extraction device, comprising: asolvent chamber having a solvent chamber return port, the solventchamber structured to store a solvent having a stored solvent volume; asolvent chamber-cannabis plant material chamber interface having a firstside and an opposing second side, the first side attached to the solventchamber and structured to receive solvent released from the solventchamber; a cannabis plant material chamber attached to the second sideof the solvent chamber-cannabis plant material chamber interface, thecannabis plant material chamber in fluid communication with the solventchamber and structured to receive the solvent released from the solventchamber, the cannabis plant material chamber structured to housecannabis plant material and to expose the received solvent to thecannabis plant material to produce a cannabinoid containingsolvent-extract solution; a cannabis plant material chamber-collectionchamber interface having a first side and an opposing second side, thefirst side attached to the cannabis plant material chamber andstructured to receive the cannabinoid containing solvent-extractsolution from the cannabis plant material chamber; a collection chamberattached to the second side of the cannabis plant materialchamber-collection chamber interface, the collection chamber in fluidcommunication with the cannabis plant material chamber and structured toreceive the cannabinoid containing solvent-extract solution from thecannabis plant material chamber, the cannabinoid containingsolvent-extract solution including at least an extracted cannabinoidproduced from the exposure of the solvent to the cannabis plantmaterial; and a solvent return attached between the collection chamberand the solvent chamber return port, the solvent return structured toprovide fluid communication between the collection chamber and thesolvent chamber; wherein the solvent chamber, the cannabis plantmaterial chamber, the collection chamber, and the solvent return form asealed, closed-cycle fluid pathway.
 27. The cannabinoid extractiondevice of claim 26, further comprising a pump disposed in one or both ofin-line with the solvent return and at a position to access any one ormore of the solvent chamber, the cannabis plant material chamber, thecollection chamber, and the solvent return.
 28. The cannabinoidextraction device of claim 26, further comprising at least one filter influid communication with one or more of the cannabis plant materialchamber, the collection chamber, and a pathway between the cannabisplant material chamber and the collection chamber, the filter structuredto prevent passage of one or more compounds into the collection chamber.